Combined gramophonic and wireless sound-reproducing means



Nov. 22, 1927. 1,650,344

E. A. GRAHAM COMBINED GRAMOPHONIC AND WIRELESS SOUND REPRODUCING MEANS Filed May 14, 1924 "Inventor- Atior'ne yr" lii Patented Nov. 22, 1927.

' resent UNITED STATES PATENT OFFICE.-

EDWARD ALFRED GRAHAM, F BROGKLEY, ENGLAND; MARIA GRAHAM AND ALFRED GRAHAM EKECUTOR$ OF SAID EDW'ARD ALFRED GRAHAM, DECEASED.

COMBINED GRAMOPHONIC AND WIRELESS SOUND-REPRODUCING 1VI'.ELA1\'|'S.

Application filed m 14, 1924, Serial 1%. 713,234, and in Great Britain February 1, 1924.

This invention relates to means wherein alternative gran'iophone and wireless loud speaker reproduction is obtained through a single soulid-conduit horn or acoustic amplifier and has for ts object to provide improved sound duct arrangements which will enable either description of sound reproduc tion to be effectively rendered without it being necessary to remove one or other of the gramophonic or telephonic rcproducers or to employ any movable valve device temporarily to isolate either reproducer to prevent sound due'to one reproducer proceed to and setting up vibration in the other reproducer.

To this end, the various sound duct arrangements according to the invention are each characterized by the fact that the duct associated with one reproducer is introduced into the duct associated with the other reproducer in such a manner that the outlet end of the introduced duct is disposed directly in the acoustic path, that is to say, sound waves originated by the first reproducer do not pass an orifice or aperture in the walls of the common duct or acoustic amplifier, but are emitted in a direction parallel with those issuing from the second reproducer. v

Further, the outlet end of the introduced duct is substantially of similar cross sectional. shape as the part of the duct into which it is introduced and has a free outlet the perimeter walls or edges of whichare uniformly separated from the wall of the outer duct by a space which is preferably constant or substantially so. Tl'ievoutlet of the inner duct is, in one form, of circularshape and is mounted in theouter duct which is also of circular cross section in such manner as to be concentric therewith. In other modified forms, the inner duct may have an orifice of rectilinear form. may be square, and in this case will be mounted within a square duct, or it the inner duct be of elliptical form it will be mounted within an outer conduit of confocal elliptical form.

Whilst an essential feature of the invention is that the outward end of the introduc tion duct is disposed directly in the acoustic path, so that sound waves originated by the reproducer first in order do not pass an orifice or aperture in the walls of the acoustic For example, it

duct, a turtherconstructional feature is that the emission orifice of the inner duct. is surrounded'on all sides by the outer duct which is of annular or equivalent formation; Various subsidiary features of importance also form part o'fthe present invention as will appear from examples now about to be described with the aid of the accompanying drawings. r

In these drawings, Fig. 1 is a partsectional elevation of one arrangement, Fig. 2 being a central vertical section at right angles to Fig. 1 of a portion of the latter. Figs. 3 and 4 are views similar to Fig. 1' of two simple modifications, Fig. 5 is a View similar to Fig. 1 of another arrangement. Fig. 6 is plan and Fig. 7 a section on the line 7-7 of Fig. 6 of yet another arrangement. Fig, 8 is a similar view to Fig. 7 showing rurther modification.

Referring first to Figs. 1 and 2, a is a mounting connecting a gramophone tone arm 6 to a trumpet c, the said mounting being formed with curved walls cl constituting an expanded region for the reception of the emission extremit e of a sound conduit f leading from a loud speaker element 7 so that a gradually developing conduit is maintained from the tone arm I) to the trumpet 0 accommodating the duct 7 intermediate of the tone arm and trumpet without obstructing the sound waves consequent upon gramophonic reproduction. To still further prevent obstruction of sound waves as referred to, the uppermost or that portion of the introduced duct directly in the path of the sound waves is of conical v tapered or stream line form allowing diversion and free passsage of sound. Waves. Such a device is shown in Figs. 1 and 2 as taking the form of a fin h. 7

Except as to proportions, the arrangement shown in Fig. 8 is practically the same as that shown in Figs. 1 and 2, the principal.

difierence being that the duct f is very much shorter. In Fig. 4 the duct 7 in lieu of being at right angles or substantially perpendicular to the axis of the mounting a is in clined and curved so as to extend through the top 2' of a cabinet or like article to receive the telephone or loud speaking element g.

According to Fig. 5, the gramophone tone are is fitted to a mounting such as a which has an extension 7' surrounded by the enlarged portion 7a of a sound duct 7 such as previously referred to the trumpet being attached to the said portion is so that in effect the gramophone sound duct may be said to be introduced into the sound duct of the loud speaker, the extension being separated from the portion k by an annular concentric aperture space on. V

In lieu of employing a special mounting, the stationary part of a tone arm, or tone arm mounting, of many existing types may be modified in construction to embody the present invention. Figs. 6 and 7 representing one example wherein the loud speaker duct f is accommodated within the mounting n of a tone arm 7), which, in known way, is supported by a bracket or arm 0 so as to be capable only of movement about a vertical axis.

A second example is illustrated by Fig. 8 wherein the mounting a of tone arm 2) is supported by a bracket or arm 0 as referred to in connection with 6 and 7, but in this case the telephone or loud speaker unit g is horizontally disposed instead of being placed in a vertical position.

What I claim is 1. In means of the kind herein referred to, a sound amplifier, a gramophonic sound duct communicating with said sound ampli fier, and a telephonic sound duct extending into said gramophonic sound duct and communicating with. said sound amplifier, the outlet end of the introduced sound duct being disposed directly in the acoustic path and at the same time marginally free from and completely out of contact with the wall of the gramophonic sound.

2. In means of the kind herein referred to, a sound amplifier, a gramophonic sound duct communicating with said sound amplifier, and a telephonic sound duct extending laterally through the wall of and intothe said gramophonic duct and having its outlet end bent and arranged co-aXial with theiduct into which it extends, the outlet end of the introduced duct being of the same cross sectional shape as the part of the duct into which is is introduced and having a free perimeter that is substantially uniformly separated from the latter.

3. In means of the kind herein referred to, a sound amplifier, a gramophonic sound duct communicating with said sound amplifier and a telephonic sound duct extending laterally through the wall of the gramophonic sound duct and having its outlet end portion arranged within such duct and at a distance therefrom such as to form an annular space therewith.

4-. In means of the kind herein referred to, a sound amplifier, gramophonic sound duct communicating with said sound amplitier and a telephonic sound duct extending into said gramophonic sound duct which is made of outwardly expanding form intermediate of i s length to accommodate the inlet end portion of the second sound duct, said ducts each havinga gradually increasing cross sectional area from its inlet to its outlet, enabling sound reproduction to be effected without obstruction of sound waves.

'5. In means of the kind herein referred to, a gramophonic sound duct and a telephonic sound duet extending laterally into the gramophonic duct and having its outlet end arranged coaxial with and out of contact with and directed toward the outlet of said gramophonic duct, the inlet end portion of the telephonic duct, on the side opposite the outlet thereof, being of tapered form to allow of diversion and free passage of gramophonic sound waves pastit.

' 6. In means of the kind referred to, a gramophonic tone arm, a stationary tubular nounting therefor forming part of a sound amplifying conduit and a second sound duct adapted to be provided with a telephonic reproducer, said sound conduit extending through the wall of and into the said tone arm mounting and'having its outlet end directed away from said tone arm and arranged to form an annular space with Said mounting.

Signed at London, England, this twentyeighth day of April, 1924.

EDWARD ALFRED GRAHAM. 

